1. Field of the Invention
The instant invention relates generally to hole boring tools and more specifically it relates to a device for and method of enlarging and center displacing a predrilled opening in a workpiece. The device for and method of precision enlarging and center displacing a predrilled opening in a workpiece can guide a hole saw to enlarge the predrilled opening in a work piece, either on center or off center with the predrilled opening. The device for and method of enlarging and center displacing a predrilled opening in a workpiece consists of a tapered knurled dowel plug having a concave cutout side less than a one hundred and twenty degree angle, to be snugly inserted quickly and safely into the predrilled opening in the work piece. A central hole and a plurality of spiral radiating repositioning center holes each act as a guide hole for the pilot drill bit of the hole saw. The concave (optionally straight or convex) cutout side will prevent the hole saw, when off center from the predrilled opening, from causing damage to the tapered knurled dowel plug.
2. Description of the Prior Art
Numerous hole boring tools have been provided in prior art. For example, U.S. Pat. No. 4,579,486 to Damico; U.S. Pat. No. 5,074,722 to Cochran; U.S. Pat. No. 5,366,326 to Converse and U.S. Pat. No. 5,658,102 to Gale all are illustrative of such prior art. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.